Petcoke piles don’t pose health hazard, says state agency
The public needn’t worry about the massive piles of petroleum coke that have been sitting for months on the banks of the Detroit River, says the State of Michigan’s Department of Environmental Quality.
According to a recently completed evaluation by the agency, available information indicates the piles “do not pose a significant public health risk for inhalation exposure.”
Concern about petroleum coke has arisen on both sides of the border since the appearance of the four-storey piles around the Detroit Harbour over the winter. The MDEQ has found that storage of the material in this open manner began last November.
The agency’s report concerns the “green” form of petroleum coke, which is a byproduct of oil refining.
According to the MDEQ, this form of the substance is “essentially inert,” and air quality staff haven’t noticed the piles generating “more than a minimal amount of airborne dust.”
The report also states that ambient air monitors in Detroit haven’t shown unusual elevations of fine particulate matter in the wind direction of the piles.
Regarding toxicity, the report notes that petroleum coke dust isn’t regulated as a carcinogenic.
Research using lab rats found no cancer after two years of inhalation exposure at 30 milligrams per cubic metre.
Exposure at 10 times those levels for 35 days had no reproductive or developmental effects on the rats.
The report says the rats “were found to have slight inflammatory responses in the lungs,” but systemic toxicity wasn’t apparent.
“It would take repeated exposure to the dust and repeated inhalation over a long period of time for it to be a health hazard,” said Andrew Hartz of the MDEQ’s water resources division.
The toxicity of “green” petroleum coke in water is also “very low,” according to the MDEQ.
Exposure tests were done with minnows and algae at concentrations of 1,0o0 milligrams per litre for 96 hours. The study found no adverse effects on the fish and only “slightly inhibited” growth in the algae.
The analysis concludes that it would require very large amounts of the material being released into the Detroit River — “tons daily” — for water quality criteria to be exceeded.
Hartz said MDEQ took the “fairly unusual” step of testing the material itself. “It’s received a lot of attention on both sides of the border.”
As for the confusion over who is legally responsible for the piles, Hartz said the MDEQ has determined that a company called Detroit Bulk Storage is the custodian of the petroleum coke where it sits on the riverfront.
Hartz said MDEQ has asked the company to apply for a permit concerning industrial storm water, and to submit a plan on “fugitive dust” during loading procedures. Responses are due soon. However, the company is not currently in violation of any regulation.
Indeed, the public may see even larger piles in the future.
“The piles are a result of the Marathon Petroleum refinery’s increased capacity to process Alberta tar sands,” Hartz said.
“As long as that refinery is processing that material, (there will be) the byproduct of that process — the petcoke.”
Hartz said MDEQ will continue to inspect and monitor the storage sites on a regular basis.
But Jim Brophy, a member of the environmental awareness group Windsor On Watch, didn’t take comfort in the MDEQ’s assurances that the petroleum coke piles meet government criteria.
“A lot of what we have for criteria is abysmal,” Brophy said. “We have ‘safe’ levels of exposure that really pose a health hazard.”
“We already have a very poisoned air shed in the west end of Windsor,” he said. “Now we’re adding this exposure.”
Brophy said he feels regulation on petroleum coke is “extremely lax,” and he remains appalled that such material can be piled so close to the Detroit River without prior controls.
“I still think it poses a potential health risk,” he said.
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